<?
class text_model extends Model
{
	    function test($user_id, $limit = '')
   {
       $sql = "SELECT DISTINCT asset_id FROM download_history WHERE user_id = $user_id AND asset_id NOT IN(SELECT asset_id FROM vote_history WHERE user_id = $user_id) ORDER BY update_time DESC $limit";

       return $this->db->getAll($sql);
   }
}